This invention relates generally to turbine engines and, more particularly, to a method and system for maintaining cooling to internal components of turbine engines.
At least some known turbine engine high pressure turbine disks include radially outer rim slots for attaching a plurality of blades to the disk using a dovetail connection. The dimensions of the slots combined with the forces exerted on the rim during various operational loadings tend to shorten the life of the disk. To strengthen the area of the rim that tends to limit the life of the disk, the dimensions of the slots may be modified. However, modification of the dovetail slot shape to increase the strength of the disk can decrease the blade cooling circuit pressure and cooling flow margins to the blades attached at the slots.
In addition, improving the life of the disk by improving the rim makes particulate erosion in forward inner shaft cavity of the disk a new life limiting area. Eliminating the particulate erosion in the forward inner shaft cavity of the disk is accomplished by eliminating the deep pocket between the shaft and the disk. However, this modification results in an excessive stress concentration at the top of the shaft air hole due to the reduction in displacement attenuation between the disk hub and the area of the shaft where the hole is positioned.